Background: Many doctors experience psychological ill health. Interns are known to be particularly vulnerable. Aim: To examine the level of depression, anxiety and stress in interns in Hong Kong, as well as the causes and how they cope. Methods: A questionnaire was designed based on the themes identified in three focus groups of medical graduates of Year 2004 of the University of Hong Kong. The 21-item Depression, Anxiety and Stress Scale (DASS 21) was also administered. All 155 graduates of the same year were invited to participate with a response rate of 63%. Results: Percentages of respondents with abnormal levels of depression, anxiety and stress were 35.8%, 35.4% and 29.2%, respectively. Frequent calls during night shift, long working hours and heavy workload constituted the most significant stressors. Factor analysis of the stressors showed that seven factors could explain 68% of the total variance: multidisciplinary team working issues, clinical difficulties, job seeking and employment, workload issues, ethical and interpersonal issues, adjustment to job rotation and performance appraisal. Holidays, peers and sleep offered the most significant relief. Conclusion: Interns experience considerable depression, anxiety and stress. The source of stress is multi-faceted, but workload is the most significant stressor. Peer support groups may relief stress.